Evan Scott and Matt Luis, firefighters with the Santa Maria fire department, monitor the Basin Complex Fire on the east side of Highway One near Esselen Institute in Monterey County on Monday, July 7, 2008. (AP Photo/ Vern Fisher, Monterey County Herald)

Photo: Vern Fisher, AP

Evan Scott and Matt Luis, firefighters with the Santa Maria fire...

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Rick Ronstadt, firefighter with the Garden Grove, Calif. fire department, works on the Basin Complex Fire on the east side of Highway One near Esalen Institute in Monterey County in Big Sur, Calif., on Monday, July 7, 2008. The fire has charred 117 square miles in the Big Sur area and was just 11 percent contained Monday. Officials said crews were burning out brush between the fire's leading edge and Big Sur's famed restaurants and hotels and cutting more lines to block flames creeping down from ridge tops. (AP Photo/Monterey County Herald, Vern Fisher)

High temperatures and low humidity are making the job of fighting wildfires in California much more difficult, state officials said Monday, but firefighters are making steady, if slow, progress against major blazes in Big Sur and Santa Barbara County.

There are 330 fires around the state and another 1,450 have been contained since June 20. In Big Sur, the Basin Complex fire had charred 80,186 acres by Monday night and was 18 percent contained. More than 2,500 homes were threatened along with 20 commercial structures and 195 outbuildings, such as sheds and barns. Twenty-three homes have been destroyed.

Experts say the blaze, which is being fought by 2,300 firefighters, won't be contained for another three weeks because of the time-consuming task of building miles of fire lines - barren spaces that will halt a fire because there's nothing there to burn.

"We've been able to make some progress, especially along the northern end of the fire," said Gregg DeNitto, an information officer at the Big Sur fire command post. The northern end is the edge that approaches Carmel Valley.

"We've built a main (fire) line there and are building another line farther away from the fire," DeNitto said.

Fire lines can be as little as a few feet wide - this happens in steep, rugged terrain where the barren area has to be literally hacked out of dense brush and trees - to as much as 200 feet wide, where the land is stripped by bulldozers.

Sunday night, fire-fighting crews unloaded half a dozen bulldozers from flatbed trucks and headed up dirt roads near the Bixby Bridge and also at Danny Ridge, off Palo Colorado Canyon, to clear out fire lines, what they call 'dozer lines. On the road near the bridge, fire crews were in luck - they found roads that had been cut through the mountains during the Maple Cone fire more than 30 years ago.

2 kinds of fire lines

On Monday, Curt Itson, a California Department of Forestry and Fire Protection battalion chief, took a Chronicle reporter 20 miles inland, up the roads near Bixby Bridge, to inspect the 'dozer lines that had been cut the night before. The huge slashes of raw dirt looked as if a giant had clawed the side of the mountains. Some of the fire lines showed signs of success - one side of the firebreak was green, the other black. And some didn't work; both sides were charred black by fire. Itson explained how the crews fight these fires.

"Basically, you need to get ahead of the fire and build a buffer," he said. "It's preferable to just cut a line by hand, but if the fire is like a freight train, you have to fight it with fire. You just need to make sure you have enough resources if it gets out of control."

Many of the lines were cut by hand - the crews call them scratch lines because they scratch the dirt with hand tools.

All along Highway 1 south of Andrew Molera State Park, firefighters had cut scratch lines right up against the road, essentially using the highway as a fire line. The scratch lines were being dug on the east or uphill side of Highway 1, in an effort to stop the fire from jumping the highway. These lines protected Pfeiffer Big Sur State Park, the Ventana Inn, Post Ranch Inn and Cooper School.

Technology aids effort

Firefighters were also relying Monday on planes with infrared equipment to locate hot spots and were using Google Earth satellite images and tips from local ranchers to pinpoint the fires' locations and which way they're heading.

Helicopters dropped water on ridge tops and 11 planes pummeled the area with fire retardant, according to John Keesee, air operations branch director for the Basin Complex fire. "It's been going very well today," he said. "We've been able to keep the fire from going past the line."

But most of the work was being done on the ground, and officials were worried about the condition of the firefighters battling the blaze. "They've been on line for a long time and are more susceptible to heat-related injuries," said Cheri Patterson, a spokeswoman for Cal Fire. "We're making sure they hydrate enough and get their (rest) breaks."

Patterson said fire-fighting teams from 41 other states have come to California.

Gap Fire 35% contained

In Santa Barbara County, U.S. Forest Service spokeswoman Norma Dailey said the 9,600-acre Gap Fire threatening the city of Goleta was 35 percent contained. Air tankers were dropping water and fire retardant, and 1,300 firefighters were building fire lines so "we can have clear defensible space," Dailey said.

Firefighters were clearing dense thickets of brush, some of it 50 years old, in steep, rocky terrain, Dailey said.

Near the coast, morning fog helped firefighters a bit, Dailey said, but "at the upper elevations it's sunny and clear, and that makes it hard for them because that inversion layer (of fog) is not reaching them."

More than 3,200 buildings are threatened in the Gap Fire, said Santa Barbara County spokeswoman Nicole Koon, and firefighters are working 12-hours-on, 12-hours-off shifts.

CALIFORNIA WILDFIRES

As of Monday, the number of active wildfires is 330. There have been 1,781 fires since June 20.

Damage: The fires have consumed 614,808 acres and destroyed 40 homes and one commercial building. They are threatening 7,610 homes and 168 commercial buildings.

Response: More than 20,000 firefighters are battling the blazes, using 1,461 fire engines, 293 bulldozers and 97 helicopters.

Largest fire: The Basin Complex fire in Big Sur has burned more acres - 80,186 - than any other fire in the state.

Fire danger: The National Weather Service warns of high fire danger through Wednesday in a number of places in Northern California, including the East Bay and North Bay hills, because of high temperatures, low humidity and breezes at high elevations.